Top: experimental workflow and schematic of the Lac-I-SceI-Tet array system. DSBs are induced with triamcinolone acetonide (TA). Middle: images form microscopy of LacO-I-SceI-TetO-U2OS cells transfected with LacR-GFP, TetR-mCherry, and HA-I-SceI-GR triamcinolone acetonide. On addition of triamcinolone acetonide, HA-I-SceI-GR translocates from cytoplasm to nucleus and induces DSB. Bottom: separated GFP and mCherry signals in LacO-I-SceI-TetO-U2OS cells depleted of indicated repair factors, mean SD (n ≥ 240 events) of three experiments. Scale bar, 5 μm.
